Tropical Storm Rafael Forecast Discussion

000
WTNT43 KNHC 050854
TCDAT3

Tropical Storm Rafael Discussion Number   7
NWS National Hurricane Center Miami FL       AL182024
400 AM EST Tue Nov 05 2024

Satellite imagery shows that Rafael is becoming better organized, 
with convective banding features becoming more prominent, 
especially over the eastern semicircle of the circulation.  Central 
convection is still a bit limited at this time, with a rather small 
Central Dense Overcast.  An earlier Air Force Hurricane Hunter 
mission indicated falling central pressure, with maximum  winds 
approaching 50 kt.  The current intensity is set at that value, 
which is slightly above the subjective Dvorak estimates, based on 
the increasing organization of the system.  Another Air Force 
Hurricane Hunter aircraft will investigate Rafael a little later 
this morning which should provide a good estimate on the strength of 
the tropical cyclone.

Rafael is moving northwestward, with an initial motion estimate of 
about 325/11 kt.  The tropical cyclone should continue this general 
motion for the next couple of days, crossing western Cuba and 
moving into the southeastern Gulf of Mexico.  The track guidance is 
in fairly good agreement for the first 48 hours of the period.  
Thereafter, the model tracks diverge with an increasing spread 
between the GFS and ECMWF solutions with time.  The ECMWF 
simulation shows a much stronger mid-level ridge over the 
southeastern U.S., resulting in Rafael moving into the western Gulf 
in the latter part of the period.  In contrast, the GFS model 
indicates that ridge will break down in 3-4 days, allowing the 
system to turn northward.  The official forecast lies roughly 
between these two possibilities and is fairly close to the model 
consensus.  This is just slightly west of the previous NHC track.  
Given the model spread, there is a less confidence than usual in the 
4-5 day forecast.

The storm is currently situated in an atmospheric and oceanic 
environment that is quite conducive for strengthening, with high 
oceanic heat content, low vertical wind shear, and high low- to 
mid-tropospheric humidity.  The various Rapid Intensification (RI) 
indices from our model guidance show a significant chance of RI 
during the next day or so, so the shorter-term official intensity 
forecast might be a bit conservative.  After Rafael moves into the 
Gulf of Mexico, however, drier air and stronger vertical wind shear 
should halt the strengthening process.  The official intensity 
forecast is on the high side of the guidance for the 3-5 day 
forecast, and is similar to the previous NHC prediction.


Key Messages:

1. Rafael is forecast to be near hurricane intensity when it passes
near or over the Cayman Islands by tonight where damaging 
hurricane-force winds, a dangerous storm surge, and destructive
waves are expected. Rafael should reach western Cuba and the Isle of
Youth on Wednesday. A hurricane warning is in effect for this
region, where a dangerous storm surge and destructive waves are
also expected.

2. Tropical storm conditions are expected in Jamaica through early 
this afternoon. Tropical storm conditions are possible in the 
Lower and Middle Florida Keys beginning late Wednesday or Wednesday 
night.

3. It is too soon to determine what, if any, impacts Rafael could
bring to portions of the northern Gulf Coast.  Residents in this
area should regularly monitor updates to the forecast.

4. Rafael will bring areas of heavy rain across portions of the 
Western Caribbean through early Thursday, including the islands of 
Jamaica and the Caymans, along with southern and western portions of 
Cuba. Flash flooding and mudslides are possible along the higher 
terrain in Jamaica and Cuba. Heavy rainfall will spread north into 
Florida and adjacent areas of the Southeast United States mid to 
late week.


FORECAST POSITIONS AND MAX WINDS

INIT  05/0900Z 17.0N  78.0W   50 KT  60 MPH
 12H  05/1800Z 18.4N  79.2W   60 KT  70 MPH
 24H  06/0600Z 20.3N  80.8W   70 KT  80 MPH
 36H  06/1800Z 22.2N  82.5W   80 KT  90 MPH
 48H  07/0600Z 23.9N  84.0W   80 KT  90 MPH
 60H  07/1800Z 25.0N  85.3W   80 KT  90 MPH
 72H  08/0600Z 25.8N  86.5W   75 KT  85 MPH
 96H  09/0600Z 26.8N  89.0W   60 KT  70 MPH
120H  10/0600Z 27.8N  90.6W   45 KT  50 MPH

$$
Forecaster Pasch